A great bronze statue of him is held at the Corrida Colosseum. Even though Kyros fought at the Corrida Colosseum only 20 years ago, no one in Dressrosa knows if he actually existed.

No one knows if he actually existed -> everyone has forgotten him. This would mean he definitely turned into a toy. That part is clear as day.

Now for my reasoning as of him being TSOR:

20 years ago TSOR must have been a young adult (old enough to have Rebecca, young enough to be Riku's son(-in-law), so he must've been 20/30-ish of age. If Kyros vanished 20 years ago and TSOR found/saved/protected Rebecca 10 years ago, it would add up. The 10 years of raising would fit in the 20 years of being a toy.